THE CLOAK OF THE OAK by David J. Ellis

Live oaks () are one of the most striking natural features in the landscape of the southeastern coastal plain. In most settings the majestic trees, often draped in a delicate mantle of silvery gray Spanish ( usneoides), are cherished for their stolid strength and the graceful spread of their branches. But in swatnps and river bottoms, live oaks can take on a primeval, even eerie look, especially at dusk or when mist ri ses around the thick trunks and the bedewed moss dangles heavily from the boughs.

Live oaks are evergreen oaks that thrive in the sandy soil and salt air of the coastal plain fron1 south to southern and then west into and north­ eastern . They are remarkable for having stubby, often buttressed trunks that quickly diverge into nearly horizontal branches, spreading up to 120 feet (33m) in diameter with a rounded crown to 50 feet (14 m) tall. The smooth­ edged, elliptical are a dark, glossy green above and pale green beneath. The tree produces yearly crops of small, elongate, dark brown acorns.

A metnber of , or the bromeliad fami ly, Spanish moss is an essen­ tially rootless that takes its water and nutrients from the air. It is com­ monly seen clinging to trees, walls, and even power lines throughout its native range, which in North America parallels not only that of live oak but also extends south to and Chile.

Usually found in clusters, individual Spanish moss are thread-like strands that can reach I 00 feet long. Each strand is punctuated at short intervals by nodes that bear a few nanow leaves and minuscule green to purple flowers with a subtle fragrance that can only be detected when they are blooming en masse. The spread­ ing of the tiny seeds is facilitated by inch-long silky threads with tiny barbs that help the seed cling to rough-barked trees. The is also spread through frag­ ments carried by wind or by birds, which used the moss for their nests.

Although Spanish moss is seen on a variety of tree species, it seems to particu­ larly thrive on Quercus virginiana. Naturalists disagree about the reasons for this association, however, and also about whether Spanish moss can be detrimental to its tree hosts. "Some people say this is an example of a nonparasitic pathogen-­ that if you get too much moss on a tree it can block photosynthesis," says Don Gardner, Director of Savannah, 's Park and Tree Department. "Maybe there have been instances where that has occuned, but I don't believe it's the case the majority of the tin1e. II Gardner believes the idea that moss can be detrimental to trees originates from an inverse conelation. "I think Spanish moss can be an indicator of vigor, but not a detenninant of vigor, II he says. "When a tree goes into decline, the leaves may get srnaller and fewer. The result is that the tree moves less in the wind and there is less opportunity for the moss to be shakerl out. II

4 jouRIInL OF rhe lnreN!1flTIO!!f7L Onk Sooe~y ISSUE 7 Craig Martin, a professor of botany at the University of Kansas in Lawrence who has been doing research on Tillandsia for about 20 years, believes the prin1ary · reasons Spanish moss has an affinity for Quercus virginiana are that the oaks' rough, gnarly bark allows the moss to take a firm hold on the tree, and that the moss may be taking up nutrients that leach out of the oaks' )eaves. "

• rely totally on aerial input for their nutrients, which they get from dust particles and whatever leaks out of what they are growing on," he says. Martin states that trees with needle-like foliage, such as , lose fewer nutrients than oaks. Mat1in's

,. research has also shown that Spanish moss grows best in light shade. The dense overhand of live oak branches may provide more shade than is available on n1ore vertically structured trees.

Quercus virginiana, often aided and abetted by their ornamenting tnoss, have a strong place in the history, literature, and lore of the South. Among the famous oaks are the Jefferson Davis Oak in Gulfport, , under which the former president of the Confederacy is said to have made a speech in 1886 urging South­ erners to forget the past and work toward a united future. The Treaty Oak in Austin, Texas, is the last of a group of Quercus virginiana under which Native Americans held councils, dances and ceremonies, and under which city founder Stephen F. Austin was said to have made the first boundary line agreen1ent be­ tween Native Americans and settlers. The Austin tree made national news in 1989 following a deliberate poisoning incident from which the tree has never fu11y recovered.

Live oaks are also connected with literature achievements. The Evangeline Oak in St. Martinsville, , was named in honor the Henry Wadsworth LongfeJlow's poem, "Evangeline," which memorialized the plight of a group of French Canadians deported from Nova Scotia to Louisiana i_n 1755.

Both species at one time had commercial value. The heavy timber of Jive oaks was prized by shipbuilders until the middle of the 19th century, and Spanish moss was used as a stuffing for mattresses and upholstery into the early part of this century. Other materials have come along to fiJI those niches, but Southern hor­ ticulturists say the charismatic combination of the Jive oak and Spanish moss is earning its keep by wowing first-time visitors to the Southeast.~

This article first appeared in the June 1995 issue of American Horticulturist (now known as The American Gardener), published by the American Horticultural So­ ciety.

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